Tag Archives: House

OCT 29 UPDATE! A Republican tsunami! My official election prediction for the House of Representatives.

This prediction has been replaced/updated with this one.

In my first analysis of the election, I forecast a Republican gain of 61 seats in the House.

In my second, I created three more sophisticated models and forecasted a GOP gain of 78 House seats. Each time a new Generic Congressional Poll was released, I updated my forecast in the comment section. I will do so again here.

The following is mostly the same text from Sunday’s post with updated polling data.

First, one must predict the vote totals for each party. Currently, RCP’s average of the “Generic Congressional Vote” shows Republicans winning 48.7% to 42.4%, a decline from Sunday’s 49.3%-41.6% margin. I then remove the polls with highest and lowest spread to eliminate outliers (in this case, I am removing one poll showing Republicans up by 14 and one that shows Democrats up by 3). Excluding those two gives us a much smaller range of +3 to +13, though this is much wider than Sunday’s range of +7 to +11, a small ver 4 point range. Removing the highest and lower outlier, Republicans lead Democrats 49.0% to 41.7%, a narrower spread than last week’s 49.8% to 40.6%. Eliminating the undecideds (if they have not decided by now, they are unlikely to vote) gives a two-party vote total of 54.0% for the Republicans (down from 55.1%) and 46.0% for the Democrats (up from 44.9%).

I now have three models to convert vote totals to House seats.

40-year model: Regression of House seats vs. vote total for every election since 1968.

8-year model: Regression of House seats vs. vote total for every election since 2002. Because of the increase in partisanship and computerized gerrymandering, there are now many more safe seats.

1994 & 2006 model: In these two mid-term elections, control of the House switched sides against an unpopular President. The same will likely occur this year.

The models produce the following results:

40-year model: Republicans win 257 House seats, gain of 79 seats.

8-year model: Republicans win 241 House seats, gain of 63 seats.

1994 & 2006 model: Republicans win 246 House seats, gain of 68 seats.

Taking a simple average of the three, I now predict the Republicans will win 248 House seats, a gain of 70 seats. On Sunday, I had predicted a gain of 78 seats. So the Generic Congressional Polls moved against the Republicans this week, but only barely.

However, the last poll of the week moved significantly in the GOP’s favor. Individual races, which had been moving against Republicans last week and earlier in this week, have also moved in the GOP’s favor toward the end of the week. I suspect that most of the movement we are seeing is statistical noise and not a change in voters’ opinions. So let’s take an average of my averages over the past week. Doing so, I now predict the GOP will gain 72 seats in the US House of Representatives.

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UPDATED! A Republican tsunami? My official election prediction for the House of Representatives.

This prediction has been replaced/updated with this one.

I have added new models to my previous prediction of a Republican gain of 61 seats in the House.

First, one must predict the vote totals for each party. Currently, RCP’s average of the “Generic Congressional Vote” shows Republicans winning 49.3% to 41.6%. However, you clearly see two outliers, one to the upside (Gallup LV Lower Turnout) and one to the downside (Newsweek). Excluding those two gives you a pretty tight pack varying from +7 to +11, a small 4 point range versus the huge 20 point range if you include the two extreme polls. Based on these five closely-packed polls, Republicans lead Democrats 49.8% to 40.6%. Eliminating the undecideds (if they have not decided by now, they are unlikely to vote) gives a two-party vote total of 55.1% for the Republicans and 44.9% for the Democrats.

I now have three models to convert vote totals to House seats.

40-year model: Regression of House seats vs. vote total for every election since 1968.

8-year model: Regression of House seats vs. vote total for every election since 2002. Because of the increase in partisanship and computerized gerrymandering, there are now many more safe seats.

1994 & 2006 model: In these two mid-term elections, control of the House switched sides against an unpopular President. The same will likely occur this year.

The models produce the following results:

40-year model: Republicans win 268 House seats, gain of 90 seats.

8-year model: Republicans win 247 House seats, gain of 69 seats.

1994 & 2006 model: Republicans win 253 House seats, gain of 75 seats.

Taking a simple average of the three, I now predict the Republicans will win 256 House seats, a gain of 78 seats.

* Again, I will update these numbers as new polls come in. But if you look at the polls on RCP over the last month, Republicans have been consistently in the lead by 8 or 9 points. Barring some late breaking change in this election, I don’t expect these number to change much. But who know how accurate the polling is this year? We won’t know for certain until November 2.